Heater for electric-lamp glowers.



No. 684,093. Patented Oct. 8, I90l. H. N. POTTER.

HEATER FDR ELECTRIC LAIP GLOWERS.

(Application Med Aug. 14, 1899.)

(lo Iodol.)

WITNESSES I TTOIIIIEY.

UNITED STATES PATENT OFFICE.

HENRY NOEL POTTER, OF GOTTINGEN, GERMANY, ASSIGNOR TO GEORGE WESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA.

HEATER FOR ELECTRIC-LAMP GLOWER S sznclrlcarxon forming part of Letters Patent No. 684,093, dated October a, 1901'. Application filed August 14, 1899. Serial No. 727,148- (No model.)

To all whom it may concern.-

Be it known that I, HENRY NOEL POTTER, a citizen of the United States of America, re" sidingin Gottingen, Germany, haveinvented certain new and useful Improvements in Heaters for Electric-Lamp Glowers, of which the following is a specification.

The problem of constructing a serviceable electric heater for use in electric lamps of the Nernst class wherein the glowers have to be brought to a high temperature before they are adapted to take enough current to maintain their luminosity without the aid of external sources of heat has been solved in va- I 5 rious ways, both for heaters which are designed to remain stationary with respect to the glowcrs and for movable heaters controlled by suitable electrical devices. I have invented a novel electric heater which is cspecially designed to serve as a stationary heater for lamps of this class, although I do not desire to limit its application to that use alone. The body of the heater which I have designed is generally tubular in cross-sec- 2 5 tion, by which I especially mean that the said body is hollow and not necessarily that it is a section of a true cylinder. This body I wind externally with a conductor or conductors designed to serve as the heating ele- 0 ments. The said conductor or conductors may be wound spirally in screw-threads or portions of screw-threads formed on the external surface of the heater-body or they may be wound around a smooth surface of a body of this type, and in either case they may afterward be covered with a paste formed from materials of the same general kind as the body of the heater itself. I generally make use of a single wire as the heating-con- 4o ductor, this wire being wound spirally around the heater-body and the separate windings being insulated from each other. In some instances I prefer to use finer wires for the heating-conductors, in which case I purpose 5 forming cables, strands, or bundles of such wires having a surface approximately equal to that of a single Wire ordinarily employed. I do not mean that I necessarily form these finer wires into twisted or braided cables, but I connect them in parallel on the surface of the heater-body in any manner.

In order to assist in localizing the heat of the electric heater, so as to produce the greatest immediate eflect upon the glower, I may flatten the top of the heater, as will be explained farther on. Moreover, I have found a certain composition to which I have given the name talcite especially adapted to serve as the heater-body in devices of this class, and I particularly desire to claim the use of this material in connection with heaterbodies of a general tubular cross-section, as set forth in this application. The material which I call talcite is made of soapstone powder in the proportions of about one hundred parts mixed with about fifteen parts of tragacanth, dextrine, or other suitable binding material and about forty parts water.

I also show and describe in this application special terminal connections for tubular heaters.

My invention is illustrated in the accompanying drawings, in which- Figure 1 is a side elevation of the body of a tubular electric heater. Fig. 2 is a similar view showing an electric terminal connected with the said heater-body. Fig. 3 is an elevation of the completed heater having the heating -conductor wound externally upon the heater-body. Fig. 4: is a view similar to Fig. 3, but showing a plurality of heatingconductors connected in parallel; and Fig. 5 shows cross-sections of various forms of tubular heater-bodies adapted for use in heaters of this class.

Referring to the drawings, A is a hollow generally tubular body of insulating heatresisting material, preferably talcite. Near the opposite ends of the body A, I make slits or notches a, and around the body and passing through the notches I wind terminal conductors I) b, so as to make good mechanical connection between said terminal conductors and the heater body. After winding the short wires in the manner described around the ends of the heater-body I generally twist the ends of the said wire together so as to leave a projecting conductor, through the medium of which it will be easy to make good electrical connection with the external conductors between which the heater is to be connected up. Instead of thus winding the terminal conductors around the ends of the heater-body I may simply thread the said conductors through the slits a a and twist the ends together as before.

In applying the heater-wire (shown at c) to the outer surface of the heater-body A, I wind the same spirally on the said body and generally connect its ends to the terminals b b by winding them around said terminals, as shown in Figs. 3 and 4.

In Fig. 5 I show cross-sections of hollow heater-bodies, one of which is strictly tubular, while the others are more or less flattened on the upper side. The object of such flattening is, as has already been set forth, to concentrate upon the glower as much of the heat radiated from the heater as can be conveniently done without sacrificing the conditions of a tubular structure for the heaterbody.

In general it may be said for heaters of the kind described above that the tubular form is especially Well adapted to admit of the heater-body being made very thin and at the same time to provide sufficient strength for ordinary uses. By virtue ofthe extreme attenuation of the heater-body it is possible to avoid undue waste of energy in heating up the supporting-body for the heatingconductor. It is alsotrue that with a very thin body of material to be heated up the act of heating is quickly accomplished, which is a desirable feature in lamps of this class.

I claim as my invention- 1.. In anelectric lamp of the class described, an electric heater consisting of a thin tubular body ot'v talcite spirally wound with a heatingconductor.

2. In an electric lamp of the class described, an-electric-heater consisting of a hollow body of talcite, and a heating-conductor secured upon the outer surface thereof.

3. In an eleetriclamp of the class described,

an electric heater consisting of athintubular body of insulating, heat-resisting material, and a heating-conductor on the outer surface of the said body, the said insulating-bod y bein g peripherally notched or perforated at each end to receive a terminal connection for. the said heater. 7

4. In an electric lam p of the class described, a thin tubular body of talcite, a heating-conductor supported on the outer surface thereof, and a terminal connection consisting of a wire or wires, the ends of which are twisted together, the said terminal wire or wires being suitably secured to the ends of the said talcite body, and the ends of the said heatingconductor being connected with the said wire or wires.

5. In an electric lamp of the class described, an electric heater consisting of a hollow body of insulating, heat-resisting material, peripherally notched or perforated at each end, a heating-conductor supported on the outer surface of the said body, and a terminal connection consisting of one or more wires which traverse the said notchesor perforations, and the ends of the heating conductor being brought together to form a means for connection with the external circuit.

6. An electric heater for lamps of the class described consisting of a thin body of talcite wound with a plurality of heating-conductors connected in parallel.

7. In a lamp of the class described, a heater consisting of a talcite tube spirally wound with a plurality of heating-conductors connected in parallel.

Signed by me at Hanover, Germany, this 14th day of July, 1899.

HENRY NOEL POTTER.

Witnesses:

W. K. ANDERSON, KIRKE LATHROP. 

